First advance in MDS for decade: Luspatercept for anemia

The US Food and Drug Administration has approved luspatercept (Reblozyl, Bristol-Myers Squibb/Acceleron) for the treatment of anemia in patients with myelodysplastic syndromes (MDS).

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The green light represents the first treatment advancement in MDS in more than a decade, says an expert in the field.

Luspatercept is the first and so far only erythroid maturation agent (EMA), and was launched last year when it was approved for the treatment of anemia in adults with beta thalassemia, who require regular red blood cell transfusions.

The new approval is for the treatment of anemia in adult patients with very low- to intermediate-risk MDS with ring sideroblasts and patients with myelodysplastic/myeloproliferative neoplasm with ring sideroblasts and thrombocytosis, after they have progressed on treatment with an erythropoiesis-stimulating agent and who require two or more red blood cell (RBC) units over 8 weeks.

Luspatercept is not a substitute for RBC transfusions in patients who require immediate correction of anemia.

The FDA approval in MDS is based on results from the pivotal, placebo-controlled, phase 3 MEDALIST trial, conducted in 229 patients with very-low–, low- and intermediate-risk non-del(5q) MDS with ring sideroblasts. All patients were RBC transfusion-dependent and had disease that was refractory to, or unlikely to respond to, erythropoiesis-stimulating agents. Results were published in January in the New England Journal of Medicine. The study was funded by Acceleron Pharma and Celgene, which was later acquired by Bristol-Myers Squibb.

These results were first presented at the 2018 annual meeting of the American Society of Hematology (ASH), as reported by Medscape Medical News. At the time, ASH President Alexis Thompson, MD, said it appears that luspatercept can improve the production of endogenous RBCs by enhancing the maturation of these cells in the bone marrow. The drug significantly reduced the need for RBC transfusions, and “this is a very exciting advance for patients who would have few other treatment options,” she said.

“Anemia and the chronic need for transfusions is a very big issue for these patients,” commented lead study author Pierre Fenaux, MD, PhD, from Hôpital Saint-Louis in Paris, France. “With low hemoglobin levels, patients are tired all the time and have an increased risk of falls and cardiovascular events. When you can improve hemoglobin levels, you really see a difference in quality of life.”

The MEDALIST trial is an important milestone for patients with lower-risk, transfusion-dependent MDS, commented Elizabeth Griffiths, MD, associate professor of oncology and director of MDS, Roswell Park Comprehensive Cancer Center, Buffalo, New York.

“No new agents have been approved for MDS in the last 10 years, highlighting this development as a substantial step forward for the MDS community,” she told Medscape Medical News. “Current therapies are time-intensive and only modestly beneficial.”

“The availability of a new, effective drug — particularly relevant to those harboring SF3B1 mutations — is an exciting development and is likely to offer meaningful improvements in quality of life,” Griffiths said. “Since these patients tend to live longer than others with MDS, there are many patients in my clinical practice who would have fit the enrollment criteria for this study. Such patients are eagerly awaiting the opportunity for a decrease in transfusion burden.”

Study Details

In the trial, luspatercept reduced the severity of anemia — 38% of the 153 patients who received luspatercept achieved transfusion independence for 8 weeks or longer compared with 13% of the 76 patients receiving placebo (P < .001).

In the study, patients received luspatercept at a starting dose of 1.0 mg/kg with titration up to 1.75 mg/kg, if needed, or placebo, subcutaneously every 3 weeks for at least 24 weeks.

During the 16 weeks before the initiation of treatment, study patients had received a median of 5 RBC units transfusions during an 8-week period (43.2% of patients had ≥ 6 RBC units, 27.9% had ≥ 4 to < 6 RBC units, and 28.8% had < 4 RBC units). At baseline, 138 (60.3%), 58 (25.3%), and 32 (14%) patients had serum erythropoietin levels less than 200 IU/L, 200-500 IU/L, and greater than 500 IU/L, respectively.

The most common luspatercept-associated adverse events (any grade) in the trial were fatigue, diarrhea, asthenia, nausea, and dizziness. Grade 3 or 4 treatment-emergent adverse events were reported in 42.5% of patients who received luspatercept and 44.7% of patients who received placebo. The incidence of adverse events decreased over time, according to the study authors.